1. Field of the Invention
The present invention relates to decorative laminates, to lay-ups for such laminates, and to methods of making such laminates and lay-ups. In another aspect, the present invention relates to multi-layered decorative laminates having a patterned depth appearance, lay-ups for such multi-layered decorative laminates, and to methods of making such multi-layered decorative laminates and lay-ups. In even another aspect, the present invention relates to a multi-layered decorative laminate where each decorative layer has a pattern off-set one from the other or each layer has the same or different pattern so that when the multi-layers are assembled into a composite structure, the resulting overall pattern has an appearance of depth or appears three-dimensional.
2. Description of the Related Art
Decorative laminates or laminates prepared by heat and pressure consolidation have been produced commercially for a number of years, and have found widespread acceptance in the building and furniture industry as counter and table tops, bathroom and kitchen work surfaces, wall paneling, partitions and doors. Such decorative laminates can be described as containing a number of laminae that are consolidated to form a composite or unitary structure carrying a surface decoration which can range from something as simple as a solid color to something as complex as an embossed simulated wood grain finish.
More specifically, a decorative laminate generally comprises plural layers of synthetic resin impregnated paper sheets consolidated or bonded together into a unitary structure under heat and pressure. In normal practice, the decorative laminate assembly, from the bottom up, consists of a core of one or more sheets impregnated with phenolic resin, above which lies a decorative sheet impregnated with melamine resin.
The core or base member functions to impart rigidity to the laminate and usually comprises a solid substrate which may or may not be formed prior to the initial laminating step. Prior to stacking, the sheets of the core member are impregnated with a water alcohol solution of phenol and formaldehyde or a formaldehyde precursor, dried and partially cured in a hot air oven, and finally cut into sheets. Examples of such a base or core member include: (1) a plurality of sheets of 90 to 150 pound ream kraft paper impregnated throughout and bonded with a substantially completely cured phenolic resin which has been converted to the thermoset state during the initial laminating step; (2) a precured plastic laminate such as glass fiber-reinforced thermoset polyester resin laminates or the like; (3) a wood product such as hardboard, woodwaste or particle boards, plywood or the like; (4) a mineral base board such as cement-asbestos board, sheet rock, plaster board or the like; or (5) a combination of these substrates.
The decorative sheet generally functions to give an attractive appearance to the laminate, and also gives the panel its surface characteristics (i.e., resistance to chemical agents, to heat, to light, to shock and to abrasion). The decorative sheet typically is a high quality 50 to 125 ream weight, pigment filled, alpha cellulose paper that has been impregnated with a water-alcohol solution of melamine-formaldehyde resin, dried and partially cured, and finally cut into sheets. The decorative sheet, prior to impregnation with the resin, may be of a solid color or may comprise a decorative design or pattern, or a photo-gravure reproduction of natural materials, such as, wood marble, leather, etc.
The decorative laminate is generally obtained by placing the resin impregnated core and decorative sheets between steel plates and subjecting the laminate stack to temperatures ranging from about 15020 F. to about 50020 F. and pressures ranging from about 800 to about 1600 psi for a time sufficient to consolidate the laminate and cure the resins (generally about 25 minutes to an hour). This causes the resin in the paper sheets to flow, cure and consolidate the sheets into a composite or unitary laminated mass referred in the art as a decorative high-pressure laminate. More than one laminate can be formed at one time by inserting a plurality of assembled sheets in a stack with each assembly being separated by a release sheet which allows the individual laminates to be separated after consolidation.
Finally, the decorative laminates so formed are bonded to a reinforcing substrate, such as plywood, hardboard, asbestos board, particle board or the like.
One drawback to these high-pressure decorative laminates are that the decorative sheet has only surface depth. Thus, the pattern imparted to the laminate by the decorative layer can only convey an appearance of depth through a patterned rendition of depth on the surface of the decorative layer. However, this surface pattern does not convey that same visual impression as structures that have visual elements that actually occur at different depths of the material and are visible to the observer's eye such as the visual appearance of most naturally occurring rocks and similar product.
There is a need in the art for high-pressure decorative laminates that have layered decorative sheets that when consolidated together produce a decorative laminate with visible features of the pattern that occur in different layers of the laminate, not just at a single decorative sheet depth as is standard in the art.
There is even another need in the art for lay-ups useful for making such above described high-pressure decorative laminates that have layered decorative sheets.
There is still another need in the art for a method of making the above described lay-ups.
There is yet another need in the art for a method of making high-pressure decorative laminates that have layered decorative sheets that when consolidated together produce a decorative laminate with visible features of the pattern that occur in different layers of the laminate, not just at a single decorative sheet depth as is standard in the art.
These and other needs in the art will become apparent to those of skill in the art upon review of this specification, including its drawings and claims.